In four wheel drive vehicles having "full time" four wheel drive such as recreational vehicles and the like, a transmission and a transfer case are provided for effecting connection between engine output to the front and rear wheels of the vehicle. Such vehicles are used both on-the-road and off-the-road. During on-the-road use, a differential drive must be provided so that slippage may occur between the front and rear axles to prevent excessive wear of tires and related problems. In off-the-road applications, it is desirable that the differential be locked such that the driving power is applied to both axles. The transfer case includes a pair of control elements shiftable into several positions. A first element is movable in one direction for high gear range drive and in a directly opposite direction to low gear range drive position. The other element is moved to provide the differential locking function. These elements are operated by a manually operated shifting stick. Ideally, the shifting stick is movable in a straight line to effect movement of the elements on the transfer case. Since movement of the control elements is separate and in one range in the opposite direction from movement of the differential locking function element, the manually operated shifting arrangement has been extremely complicated both from an operator's standpoint and also because of the expense involved in constructing such shifting mechanisms. Heretofore, of necessity, such shifter assemblies were complicated in construction and required a great many component parts.
In the prior art, various control mechanisms have been proposed. One such prior art mechanism is shown in commonly assigned U.S. Pat. No. 3,902,378 issued Sept. 2, 1975 entitled STRAIGHT-LINE SHIFTING ASSEMBLY. Systems of this type, are relatively complicated and expensive to manufacture.